The present invention relates in general to masks for the administering of anesthetic gas to a patient, and more particularly to a mask suitable for the administration of anesthetic gas to a dental patient.
Heretofore, it was the general practice for dentists to use the same mask on a plurality of patients for the administration of anesthetic gas. Such practices were of concern to the dentist, as well as the patient, because of the possibility of cross-contamination. In certain instances, the entire dental mask was intended for single patient use.
In the Glenn E. Brown U.S. Pat. No. 4,015,598, issued on Apr. 5, 1977, for Anaesthesic System, there is disclosed a mask for the administration of anesthetic gas to a dental patient. The mask comprises an inner cup-shaped wall to fit over the nose or the mouth of a patient. The inner wall engages the face of the patient along the peripheral edge of the inner cup to form a gas chamber between the face of the patient and the inner surface of the inner wall. An outer cup-shaped wall was secured to and spaced from the inner wall to form an exhaust passage between the inner and outer walls. The exhaust passage communicates with the gas chamber when the patient exhales. The peripheral edge of the outer wall is disposed in the vicinity of the peripheral edge of the inner wall to draw into the exhaust passage gas leaking between the face of the patient and the inner wall. Gas is introduced into the chamber to be inhaled by the patient. A valve is interposed between the inner and outer walls and is opened to permit exhaust gas to flow into the exhaust passage from the gas chamber when the patient exhales. When the patient inhales, the valve is closed blocking the passage of gas from the gas chamber to the exhaust passage.
The Czajka U.S. Pat. No. 4,219,020, issued on Aug. 26, 1980, for Scavenger Valve Attachment For Inhalation Sedation System Mask, discloses a scavenging attachment mounted on a face mask. An exhalation aperture leads through a floating disc check valve to a vacuum chamber which extends in a generally concave inverted saucer configuration over and around the mask. The vacuum chamber communicates with the surrounding atmosphere by means of an annular aperture in order to scavenge from the atmosphere adjacent the patient's face any gas escaping from the periphery of the mask.
MDT McKesson has sold a Twin-Trac Scavenging Mask having a disposable safety seal that was removably attached to the perimeter of the mask and engageable with the face of the patient. The tubing connecting the mask is adjustable by normal movement to accommodate patient position and movement. Additionally, the entire unit is heat and steam sterilizable including the tubing by well-known and conventional procedures.
In the Brekke et al. U.S. Pat. No. 4,151,843, granted on May 1, 1979, for Apparatus For Administration Of A Gas To A Human And The Exhausting Thereof, there is disclosed a mask for the administration of anesthetic gas to a patient in which the mask thereof is hollow and covers the entire nose. The mask terminates in two projections on its inner surface which engage the external portion of the nasal orifices bilaterally, thereby preventing leakage of gases out of or into the system at that point.
The Myers U.S. Pat. No. 3,721,239, issued on Mar. 20, 1973, for Anesthetic Gas Exhaust System, discloses an exhaust system for removal of anesthetic gas from an operating theatre. The manifold for the system has tubing attached thereto and is connected to the suction system. Attached to an end of the tubing is a corrugated hose which is flexible and which is corrugated in a bellow fashion.
The McKesson U.S. Pat. No. 1,632,449, issued on June 14, 1927, for a Mask, discloses a mask that fits over the nose of a patient for the administering of anesthetic gas. The mask includes an elastic flap that extends inwardly from the mask opening.
In the Bartlett, Jr. et al. U.S. Pat. No. 3,395,701, issued on Aug. 6, 1968, for End Tidal Sampler For An Oxygen Breathing Mask, there is disclosed a standard oxygen mask. The upper portion of the mask has an inwardly directed section that appears it may fit over the entire nose of the user.
Accutron of Phoenix, Arizona has manufactured and sold a dental mask with a valve. The single cup-shaped wall mask has a valve seat with openings formed therein as part of the single cup-shaped wall. The valve includes a valve disc that normally covers the openings by seating against the valve seat to close the valve. When the patient exhales, the valve disc is displaced from the valve seat to open the valve. The gas chamber of the dental mask communicates with an exhaust system through the opened valve. The valve disc is axially attached to the valve seat at the hub thereof.